MiR‐181a‐5p promotes neural stem cell proliferation and enhances the learning and memory of aged mice

Hippocampal neural stem cell (NSC) proliferation is known to decline with age, which is closely linked to learning and memory impairments. In the current study, we found that the expression level of miR‐181a‐5p was decreased in the hippocampal NSCs of aged mice and that exogenous overexpression of miR‐181a‐5p promoted NSC proliferation without affecting NSC differentiation into neurons and astrocytes. The mechanistic study revealed that phosphatase and tensin homolog (PTEN), a negative regulator of the AKT signaling pathway, was the target of miR‐181a‐5p and knockdown of PTEN could rescue the impairment of NSC proliferation caused by low miR‐181a‐5p levels. Moreover, overexpression of miR‐181a‐5p in the dentate gyrus enhanced the proliferation of NSCs and ameliorated learning and memory impairments in aged mice. Taken together, our findings indicated that miR‐181a‐5p played a functional role in NSC proliferation and aging‐related, hippocampus‐dependent learning and memory impairments.